Withanolide A series steroidal lactones from Eucalyptus globulus bark

A new steroidal lactone of the Withanolide A series has been isolated from the supercritical fluid extract of Eucalyptus globulus L. (bark) as a major component (I) along with a known structurally similar steroidal lactone as minor component (II). The structural identification of the new lactone was accomplished by different spectroscopic techniques viz. 1H and 13C NMR, etc. The relative stereochemistry was unequivocally determined from the X-ray crystallography.

Graphical abstractA new steroidal lactone of the Withanolide A series (+)-6α,7α-epoxy-5α-hydroxy-1-oxowitha-2, 24 dienolide molecule has been isolated from the supercritical fluid extract of Eucalyptus globulus L. (bark).Download full-size image